It seems based on your later comments that the premise of marketing worlds existing relies on there being trade-offs between our specified wants and our unspecified wants, so that the world optimised for our specified wants must necessarily be highly likely to be lacking in our unspecified ones ("A world with maximal bananas will likely have no apples at all").

I don't think this is necessarily the case. If I only specify that I want low rates of abortion, for example, then I think it highly likely that 'd get a world that also has low rates of STD transmission, unwanted pregnancy, poverty, sexism and religiousity because they all go together, I think you could specify any one of those variables and almost all of the time you would get all the rest as a package deal without specifying them.

Of course a malevolent AI could probably deliberately construct a siren world to maximise one of those values and tank the rest but such worlds seem highly unlikely to arise organically. The rising tide of education, enlightenment, wealth and egalitarianism lifts most of the important boats all at once, or at least that is how it seems to me.